Analog Connections; Analog Output Networks; Digital Connections - Pacific Microsonics HDCD Model Two User Manual

Installation
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Model Two HDCD User's Manual

Analog Connections

Analog Input and Output connections on the Model Two are balanced, using 3-pin XLR
connectors with either pin 2 or 3 set as hot (software selectable) and pin 1 as ground.
Input impedance is 13 k balanced ( 6.5 k per leg); output impedance is 20
balanced (10 per leg). If the audio source driving the Model Two is single ended, a
balanced interconnect cable should be used with the return wire tied to ground at the
sending end. If the audio output from the Model Two must drive an unbalanced load, use
pin 2 as high, pin 1 as ground, and lift pin 3 at the load or use pin 3 as high, pin 1 as
ground, and lift pin 2 at the load. CAUTION: Never connect the unused low pin to
ground, (pin 1) as that will short circuit one side of the Model Two's actively bal-
anced, DC coupled, output amplifier, and seriously degrade performance.
Analog audio connections and grounds should be isolated electrically and physically from
digital signals, power conduits, and other noise sources. Audio cables should have low
impedance grounds and one-hundred percent RF shielding. Cables using a foil shield and
drain wire construction should not be used. They can produce voltages in the signal path
due to ground currents flowing between different pieces of equipment.

Analog Output Networks

HDCD Processor Analog Output Networks (AON's) are designed to improve the high fre-
quency impedance match between the Model Two's D/A analog output impedance, which is
about 10 per leg, and the characteristic impedance of typical analog audio cables,
which is about 60 . The improved impedance match better terminates reflected high
frequency energy in the cable, which can improve sonic clarity and purity. The AON's are
designed to be connected between the Model Two's analog outputs, and the audio cables
used to feed the monitoring system. Two AON's are provided with each Model Two.
Use of the AON's is optional. Depending on system variables, including the power band-
width and type of monitor power amplifiers used, and the length of audio cables, the
sound quality of the Model Two's D/A's may be preferred with or without the AON's. It is
best to experiment by listening to a wide variety of different types of source material, both
with and without the AON's installed. Note: The AON's should be used only with load
impedances that are greater than 4 k balanced (2 k per leg). The AON's are designed
only for use with the Model Two. Use with other products is not recommended and may
result in unsatisfactory performance.

Digital Connections

The Digital Inputs and Outputs use 3-pin XLR connectors with pins 2 and 3 active, and pin
1 connected to chassis ground. Input and output impedances are 110 balanced. The
signal format is AES3.
P A C I F I C M I C R O S O N I C S I N C .
Rev. C - January 2002
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